OLIGHT M3X PROBLEM

Hi, when i run the light without the extension tube everything seems fine. But when i use the extension tube with 18650 batteries once the light is turned on it will go off and on at random, seems to turn off when i point it downwards or knock it. Is this a common problem?? iv checked everything is tight but this actually seems to be the problem.... if i back the extension tube off a bit and then back the pocket clip ring back to it to 'lock' the extension tube slightly off the main body it seems to work perfectly?! I use either xtar 18700 or tank 007 18650 batteries.
So basically im wondering if there is actually a problem with this light or am i just being petty??
Any help would be gratefully appreciated
Ady

Sooo...let me see if I understand this? You are using a battery that is 70mm long in addition to one that is 65mm long inside a flashlight tube that is clearly designed for two batteries each 65mm long and having problems with it working properly? You are wondering if this is a problem wih the flashlight?

Are you joking? Seriously I am not sure....I guess I don't understand how this is not obvious? The problem is that you are using a battery that is not intended for use in this light and takes up another 5mm of space which is about the length of the negative contact spring in the tailcap. You are pressing the contact against the switch mechanism which in turn is causing the switch to bind up.

I would suggest that you try using the batteries the flashlight was designed for before calling into question the manufacturing quality of the light.

no they are the two different types i use, obviously i match batteries im not daft. the xtar 18700 are actually 18650 if you look it up.... its just the protection circuit in them as to why they call them 18700.
there actually isnt a true 18650 if my understanding is correct now as most have a protection circuit that makes them a little longer than 65mm
i belive the lenth of the battery is the answer to this though..... but im definatly not going to start using unprotected cells.

Did you try putting the extension and tailcap on and installing the batteries through the front before putting the head on? On my M3X you barely have to turn the body/extension threads to make the light go out.

yes tried that... only thing that works is if i back the extension tube off from the main body. it just doesnt seem right to have to do that?

Now something I was just thinking about is that if the retaining ring inside the tailcap were a little loose in addition to the added length of batteries....it could also cause the switch to bind. Something worth checking out.

I was just looking at my M21 a little closer and with an 18650 cell in place...the back of the cell is flush with the top of the battery tube, there is no room to spare. While the spring in the tailcap is about 5mm long, it only has about 3mm of travel before it stops completely. While I can't say an extra 2-3mm would cause a problem with the switch....it would be difficult to get it to fit since the plunger would stop the tailcap from screwing on far enough to make full contact with the tube and complete the electrical circuit.

lightfooted said:

Now something I was just thinking about is that if the retaining ring inside the tailcap were a little loose in addition to the added length of batteries....it could also cause the switch to bind. Something worth checking out.

Click to expand...

I agree with this as a possible issue, mine was loose when it arrived.

adyscarborough said:

only thing that works is if i back the extension tube off from the main body. it just doesnt seem right to have to do that?

Click to expand...

This sounds exactly like the retaining ring to me.


EDIT: with 3 primaries it works because the cells sit more even with the end of the body. Add the extension and the 2x18650's sit "just out of" the body, at least on mine with redilast 2900's they do. If the retaining ring is somewhat loose it can work fine until the added pressure of the longer cells pushes on it causing the switch to break contact with the retaining ring and opening the circuit.


3x123 Surefire cells.



2x18650 Redilast cells.



This small amount of difference is all it took to make mine act similar to yours until I tightened the retaining ring on the switch.

Here's a picture of the inside of the tail switch.




Use snap ring pliers or anything that will fit into the 2 holes and tighten it clockwise. I have ran into some tailswitches that have reverse threading for the switch part is why I mention the direction, not trying to insult anyone here.


One more suggestion. Take off the tailcap and make a "bridge" between the body end and the battery end. Use a SPOON, place the bottom of the spoon on the battery end and you can use your thumb "IN the spoon" to hold it down (similar to a momentary button. Doing it this way allows you to use the light in a normal fashion to see if you can replicate any malfunction while moving the light around. I just tried this and it works beautifully.

I have same problem with my Olight M3X and 2 x Redilast 18650 cells. The problem is that the cells are too long. You can unscrew the tailcap slightly which helps a little. I just use AW 18650 3100mAh with no problems. You can always play around with the tailcap and screw it in a little tighter. That may help.

yes i also tried tightening that as i knew of that problem before.... i belive the problem is the length of the cells also..... the tank 007 18650 are 68.5 mm long..... with two of these is a full 7mm more than it should be i think. somebody actually said it could be crushing the cells and causing them to act in this way. as iv tried the cr123 primarys and have no issues.

My Redilast work, same length. Mine don't have any crush marks. The only other thing I can think to check is the two posts, the one in the head and the one in the tail to see if the spring behind them is moving correctly. I can push my 18650's in just past the end of the body with the tail off.

My Redilast cells work sometimes, but I do believe the problem is the length of the cells, as I never have any problems with the slightly shorter AW high capacity 18650 cells.

iv actually contacted olight about this and they seem to think this is strange behaviour for the light :-/

think2x said:

Use snap ring pliers or anything that will fit into the 2 holes and tighten it clockwise. I have ran into some tailswitches that have reverse threading for the switch part is why I mention the direction, not trying to insult anyone here.

Click to expand...

I know this is an old post, but I wanted to thank you so much for it because it fixed my problem.

I recieved my new M3X yesterday and was having problems with getting the light to turn on using 2 18650 protected cells. It seemed only to turn on when the extender was backed off and even then it was not consistent. Sometimes I needed to press the clicker really hard to get it to light and then it wouldn't even stay on. I felt really bummed because I couldn't figure out the pattern.

Tightening the tail switch cured it of all problems. Everything, including the extender, is all tight and the switch works reliably and I am excited again about my purchase . It's amazing how less than a quarter of a turn can make such a difference--Thank you!

Glad the info helped.

I've got one more question. The tail switch continues to loosen from the simple action of unscrewing the cap. Over time, the problem re-occurs and I need to tighten it again.

Would it be alright if I put a couple of drops of Loctite on there?

I have Blue 242 (removable) so it's not that strong, but I wonder if it would be good enough to keep it from loosening on its own and not wreck anything with the electronics.

Should be fine to use the blue.